Final answer:
Another legal method to signal a left turn besides using the left turn signal light is to point the left arm straight out the left window of the vehicle.
Step-by-step explanation:
The most common way to signal a left turn other than using your left turn signal light is to point your left arm straight out the left window. This is a universally recognized hand signal that indicates your intention to turn left. It is important to note that hand signals should only be used as a backup if your vehicle's turn signal lights are not functioning properly.
Besides using your left turn signal light, another legal way to signal a left turn when driving a vehicle is to use hand signals. Specifically, you can use your left arm to signal your intended movements. For a left turn, you should point your left arm straight out the left window.